In the construction industry, it is necessary to estimate the total costs of the materials and other items required for a construction project prior to starting the project in order to determine the total cost of the project. It is customary for an estimator performing such an estimate to make the estimate using the blueprints that have been prepared for the project. The estimator reviews each blueprint required to specify the project and determines the total quantity of each item required by the blueprint. It is common for each contracting entity in the construction industry to perform its own quantity takeoff for its own needs.
The determinations made by an estimator when performing a quantity takeoff estimate include determinations of the total area over which an item is required or the total quantity of an item required in the blueprints. For example, the takeoff estimator can determine the total area of a type of carpeting that is required for a construction project or the total number of electrical outlets required for the project by reviewing the blueprints. The determinations often must be made for all surfaces and/or materials in the construction project, including vertical surfaces. In combination with the cost per unit for each required item, the estimator uses the quantity determinations to estimate the total cost of all the items specified by the blueprints.
One well known method of performing a takeoff estimate is the manual method. In the manual method the estimator used a ruler or other measurement device to manually measure the various areas specified by the blueprint and recorded the information on a note pad. This method of recording quantities was tedious. In a manual estimation the estimator added a number of manually measured and calculated quantities using, for example, a paper note pad in order to determine the total quantity wherein a particular item was specified.
For example, using manually measured and calculated quantities designated on a blueprint as requiring a particular type of carpet, the estimator estimated the total area of the carpet. The manually determined areas obtained in this manner were noted and scaled by the estimator according to the scaling set forth on the blueprint. Additionally, the estimator manually counted and noted the number of electrical outlets and manually measured the length of the different types of wire and piping. The values determined and noted from the blueprint in this manner were added together in order to determine the totals for each item on the blueprint.
All of the takeoff information manually determined from a blueprint in this manner was manually indexed to the blueprint from which it was gathered in order to permit the quantity takeoff information to be associated with the blueprint at a later time. The estimator then proceeded to the next blueprint and determined the takeoff information in the same manner. When all of the blueprints were processed the estimator added the values obtained for each item from each of the blueprints of the collection of blueprints in order to determine the total in the entire project for each item.
Alternately, estimators performed the manual estimation method by selecting an item for determination and proceeding from one blueprint to another, adding up all of the occurrences of the selected item on all of the blueprints. For example, the estimator proceeded through the blueprints of a construction project and measured all of the areas requiring a specified type of tile on each blueprint. The total requirements were then determined by adding the amounts required by all of the blueprints. This was repeated for each item.
In order to limit the number of errors that can occur when performing the manual estimation method, the estimator customarily checked off each item as it was measured or counted and each area of a blueprint when it was completed. While the determinations with respect to certain countable items, such as electrical outlets, could be performed relatively efficiently using one of the manual methods, the manual methods of performing the construction quantity takeoff estimates were typically very laborious. Additionally, the manual methods were error prone. Errors made in performing these estimates resulted in waste due to under ordering or over ordering items or errors in bidding due to mis-counting items for the construction project.
Another method of performing estimates from construction blueprints was by determining the areas corresponding to the items specified by the blueprints using a digitizer rather than manual measurements. When performing a digitizer method of area quantity takeoff the estimator touched a digitizer pen to each corner of or traced the perimeter of an area of a blueprint to be measured. Provided the estimator thereby defined a closed polygon the total area bounded by and the total length of the lines connecting the points touched by the digitizer pen was calculated by a computer that is coupled to the digitizer. Digitizers can be advantageously applied in this manner to irregularly shaped areas specified in a blueprint and also applied to calculation of line lengths of linear building features and counts of unit building features.
The application of digitizers to calculating material and cost estimates from plans such as blueprints is taught in U.S. Pat. No. 4,578,768, issued on Mar. 25, 1986, to Racine (the '768 Patent). In the embodiment taught by the '768 Patent an L-shaped frame includes linear microphones that are disposed at a right angle with respect to each other on a flat surface in order to provide a sensor assembly. The blueprint is disposed upon the flat surface adjacent the sensor assembly. Points on the blueprints are touched by a hand held stylus adapted to emit a sound when touched to the surface. In this manner, the system taught by the '768 Patent determines the X-Y coordinates of the locations touched by the stylus. A keyboard entry device is also taught, as well as a printer and a video display for providing representations of information such as material and cost estimates.
A menu is provided on the flat surface of the digitizer in order to permit the estimator to use the stylus for indicating functions and information, such as units conversions, and programs for calculating weights. A plurality of different menus can be used. Thus, using the method taught by the '768 Patent, the estimator must repeatedly move the stylus back and forth between the blueprint and the menu in order to enter both the blueprint information and the functions and information set forth on the menu.
U.S. Pat. No. 4,782,448, issued on Nov. 1, 1988 to Milstein, teaches another prior art device for estimating the costs of a construction project. The device taught by Milstein includes a hand held stylus and a digitizer having a menu. The system of Milstein permits an estimator to indicate component parts, sizes, and scale factors using the menu. Based upon the input information received from the stylus a computer coupled to the digitizer counts the number of each size of each component and calculates the total length of pipes and other components.
U.S. Pat. No. 4,811,243, issued on Mar. 7, 1989, to Racine (the '243 Patent) teaches another system for calculating data such as material and cost estimates from plans such as blueprints. In the '243 Patent a digitizer device determines the X-Y coordinates by means of a stylus. The '243 Patent also teaches the use of a voice recognition unit to receive input information from the estimator and to convert the voice commands of the user into computer control signals. The computer control signals operate the computer and initiate selected computer programs for performing construction estimates. The system taught by the '243 Patent does not permit the estimator to enter numerical data using the voice recognition unit. Thus, an estimator using the system of the '243 Patent must repeatedly move the stylus back and forth between the blueprint and the menu in order to enter both the blueprint information and the functions and information of the menu.
Therefore, the use of digitizer systems within the prior art of takeoff estimates can require excessive repetitive motion by the estimators resulting in slower takeoff estimates. The excessive repetitive motion puts estimators using the digitizer systems at risk for injuries such as carpel tunnel syndrome. Furthermore, digitizer systems are difficult to transport, require too much space to be conveniently set up, and are expensive.
Another problem with using known digitizer systems for performing quantity takeoff estimates is that it is difficult for an estimator to freely switch from one blueprint to another. The difficulty occurs because a blueprint must be securely fastened to the flat surface of a digitizer in order to prevent any movement of the blueprint with respect to the flat surface that would result in inaccurate measurements. The secured blueprint must therefore be detached from the flat surface in order to permit switching to another blueprint. Since such switching between blueprints is an operation that is frequently performed during quantity takeoff estimates, difficulty in performing the switching is a serious drawback.
U.S. Pat. No. 5,389,917, issued to LaManna on Feb. 14, 1995, teaches a lightweight data entry terminal having a microphone adapted to be worn by the user on a lapel while the user performs a function such as inventory management. Entry of data such as product codes can be performed by verbal pronouncements into the microphone as well as by optical scanning using the system taught by LaManna. The data acquired by LaManna in this manner is transmitted to a central communication center. The LaManna system does not perform the calculations necessary for the inventory management function in response to user instructions.
Another prior art method of performing takeoff estimates uses computer aided drafting (CAD) drawings. When CAD representations of the blueprint information are available to estimators it is possible to automate the determination of certain required quantity information for the items specified by the blueprint. In the CAD method of performing takeoff estimates CAD representations are inputted directly into a computer. The computer is programmed to receive the CAD representations and calculate some of the information required for preparing takeoff estimates therefrom. Devices for receiving CAD drawings in this manner can determine the dimensions of selected areas defined on the blueprints.
However, CAD representations of the blueprint information are not readily available to contractors within the construction industry. One reason for the lack of availability of CAD representations is that many areas of the construction industry are still distrustful of computerized methods. Furthermore, the known devices do not provide takeoff estimate reports or all of the information required to provide such reports.
For the various methods of determining takeoff information, computer networkbased construction services for distributing the takeoff information after it is determined are known in the prior art. The prior art distribution services include automated commerce and procurement performed within systems where a network of buyers and sellers automatically negotiate purchases and sales in accordance with information distributed within the network.
Another prior art construction service available within computer networks is a project hosting service. In the project hosting service computer storage and distribution and tracking of project documents is provided by way of a computer network. Another prior art service offered includes marketing and prospecting services. While these services available within computer networks may rely upon abstracted takeoff data, none of these services develops or distributes raw construction project data that serves the basis for construction quantity takeoff work.